Hi! I haven't submitted any runs on here but I did start speedrunning this while it was still a demo. My ideas are:

All Endings (Including DLC) (-1 to 16) 100% (All Endings -1 to 16 and all secrets and achievements) All DLC Endings (13 to 16)

Also, maybe each individual ending should go into a level leaderboard instead of the main one

Yeah i agree i think the DLC should be part too as its free for everyone.